1/* 2 * Copyright (c) 2019-2019 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29#ifndef _IOKIT_OSACTION_H 30#define _IOKIT_OSACTION_H 31 32#include <DriverKit/OSObject.iig> 33 34typedef void (^OSActionCancelHandler)(void); 35typedef void (^OSActionAbortedHandler)(void); 36struct OSActionWaitToken; 37class OSString; 38 39/*! 40 * @class OSAction 41 * 42 * @abstract 43 * OSAction is an object that represents a callback to be be invoked. 44 * 45 * @discussion 46 * The callback is specified as a method and object pair. 47 * State associated with the callback may be allocated and stored for the creator of the object. 48 * Methods to allocate an OSAction instance are generated for each method defined in a class with 49 * a TYPE attribute. The generated methods are named CreateAction{name of method with type attribute} 50 * and have the following declaration: 51 * 52 * kern_return_t CreateActionNameOfMethod(size_t referenceSize, OSAction **action); 53 * 54 * referenceSize refers to the size of additional state structure available to the creator of the OSAction 55 * with GetReference. If successful, the generated method returns kIOReturnSuccess and a created OSAction 56 * through the 'action' parameter with a +1 retain count to be released by the caller. See IOReturn.h for 57 * error codes. 58 */ 59 60class NATIVE KERNEL OSAction : public OSObject 61{ 62public: 63 64#if DRIVERKIT_PRIVATE 65 /*! 66 * @brief Create an instance of OSAction. 67 * @discussion Methods to allocate an OSAction instance are generated for each method defined in a class with 68 * a TYPE attribute, so there should not be any need to directly call OSAction::Create(). 69 * @param target OSObject to receive the callback. This object will be retained until the OSAction is 70 * canceled or freed. 71 * @param targetmsgid Generated message ID for the target method. 72 * @param msgid Generated message ID for the method invoked by the receiver of the OSAction 73 * to generate the callback. 74 * @param referenceSize Size of additional state structure available to the creator of the OSAction 75 * with GetReference. 76 * @param action Created OSAction with +1 retain count to be released by the caller. 77 * @return kIOReturnSuccess on success. See IOReturn.h for error codes. 78 */ 79 static kern_return_t 80 Create( 81 OSObject * target, 82 uint64_t targetmsgid, 83 uint64_t msgid, 84 size_t referenceSize, 85 OSAction ** action) LOCAL; 86 87 static kern_return_t 88 CreateWithTypeName( 89 OSObject * target, 90 uint64_t targetmsgid, 91 uint64_t msgid, 92 size_t referenceSize, 93 OSString * typeName, 94 OSAction ** action) LOCAL; 95#endif 96 97 virtual void 98 free() override; 99 100 /*! 101 * @brief Return a pointer to any state allocated by the OSAction creator. 102 * @discussion Reference data is allocated with zero initialized content. It may be set and retrieved later 103 * with this method. 104 * @return A pointer to storage for the owner. It will be NULL if referenceSize was zero, and NULL 105 * when called in a process other than the owner that is receiving the OSAction as a parameter. 106 */ 107 void * 108 GetReference() LOCALONLY; 109 110 /*! 111 * @brief Cancel all callbacks from the action. 112 * @discussion After cancellation, the action can only be freed. It cannot be reactivated. 113 * @param handler Handler block to be invoked after any callbacks have completed. 114 * @return kIOReturnSuccess on success. See IOReturn.h for error codes. 115 */ 116 kern_return_t 117 Cancel(OSActionCancelHandler handler) LOCALONLY; 118 119 /*! 120 * @brief Install a handler to be invoked when no other processes reference the action. 121 * @discussion When all tasks other than the creator release their references to the action, 122 * invoke the handler in the owner. A task exiting will always remove its references. 123 * @param handler Handler block to be invoked on no more references. 124 * @return kIOReturnSuccess on success. See IOReturn.h for error codes. 125 */ 126 kern_return_t 127 SetAbortedHandler(OSActionAbortedHandler handler) LOCALONLY; 128 129 /*! 130 * @brief Mark this OSAction to be waited for later with Wait(). 131 * @discussion This call should be made before any possible invocation of the action. 132 * An OSAction instance only supports one waiter and WillWait() will return an error if already called. 133 * @param token Opaque value to be passed to a later call to Wait() and EndWait(). 134 * @return kIOReturnSuccess on success. See IOReturn.h for error codes. 135 */ 136 kern_return_t 137 WillWait(OSActionWaitToken ** token) LOCALONLY; 138 139 /*! 140 * @brief Discard the OSActionWaitToken for the action. 141 * @discussion Free any resources needed to wait for the action allocated by WillWait(). 142 * There should be no outstanding invocations of the action when EndWait is called, 143 * if necessary the action should be canceled before calling EndWait(). 144 * @param token Opaque value to be passed from an earlier call to WillWait(). 145 * @return kIOReturnSuccess on success. kIOReturnAborted if aborted or canceled. 146 kIOReturnTimeout if the deadline was passed. See IOReturn.h for error codes. 147 */ 148 kern_return_t 149 EndWait( 150 OSActionWaitToken * token) LOCALONLY; 151 152 /*! 153 * @brief Wait for the action to be invoked. 154 * @discussion The current thread is blocked until the action invocation has completed, the action canceled 155 or aborted, or the deadline passed. 156 * @param token Opaque value to be passed from an earlier call to WillWait(). 157 * @param options Pass one of the kIOTimerClock* options to specify the timebase for the 158 * deadline, or zero for no timeout. 159 * @param deadline Pass the time the wait should timeout, or zero for no timeout. 160 * @return kIOReturnSuccess on success. kIOReturnAborted if aborted or canceled. 161 kIOReturnTimeout if the deadline was passed. See IOReturn.h for error codes. 162 */ 163 kern_return_t 164 Wait( 165 OSActionWaitToken * token, 166 uint64_t options, 167 uint64_t deadline) LOCALONLY; 168 169 virtual void 170 Aborted(void) LOCALHOST; 171}; 172 173#endif /* ! _IOKIT_OSACTION_H */ 174